st: Shorthand way of applying an IF to several variables.

I have, say, 500 observations and 300 variables. I want to do a TABSTSAT
that has an IF condition such that any observation is not to be included
in the tabstat if the value of any variable is zero or missing. I know
how I can do this the long way, but could someone tell me how, or where
I can find out how I can use an operaion that would save me having to
list each of the 300 variables in the IF condition?